This phenomenon was attributed to 2,4-D which stimulates uncontrolled cell growth and proliferation in treated plants. This may have also skewed the control data on the larger sicklepod plants which would lower the control rating by 2,4-D alone treatments and to a lesser extent, the dicamba alone treatments. These effects were not observed with the Palmer amaranth or pitted morningglory stem diameters. Parthenium hysterophorus L. is of great concern among the invasive alien plant species identified in Ethiopia. It causes several ecological and agricultural problems, such as the loss of crop productivity, fodder scarcity, biodiversity depletion, and health problems to human beings and livestock Based on its impact on food production, plant biodiversity, and animal and human health, it is ranked number one before Prosopis juliflora, which is aggressively invading most grazing lands and arable lands in the Northeastern part of Ethiopia Though cattle do not eat Parthenium, its effects were observed on them when they walk-by or graze through patches of this weed.
The plant also negatively affects foraging behavior and flower visitation by bees First introduced in the 1970s, it has rapidly invaded diverse habitats, including roadside, grassland, and crop fields in the central, eastern, and northern Ethiopia Recent investigations showed that the weed has already conquered the arable and grasslands, mainly in East Shewa, West Shewa, Arsi, and the other fertile zones in Oromia Regional states At present, the weed has already established itself in almost every region of the country So far, there is no recommended effective control method for this menacing weed other than cultural control such as hand hoeing and slashing/chopping before flowering. The nature of proliferation, strong reproductive potential,grow cannabis and wide ecological range of adaptation makes the eradication of Parthenium challenging . Since the weed has great regeneration potential, its control using biological agents like beetles , weevil , and leaf rust have resulted in little success. Burning is effective in destroying the whole part of the plant but not recommended as it deteriorates the soil quality. Even though prolonged contacts with Parthenium plant can cause skin itching and dermatitis, hand hoeing proved to be more efficient than the use of herbicide .
Thus, preventing the distribution and establishment of the weed from a new area is crucial. In Metekel Zone , even though some scholars have reported its presence there was no report of severe invasion of Parthenium on agricultural lands up to date. Despite having fertile and virgin land, which is enormously suitable for crop and animal production, MZ had been less disturbed by cultivation compared to the northern and eastern parts of the country. However, recently, cultivation is dramatically increasing as the improved infrastructure and development attracted more investors to the area. This situation, coupled with persisting climate change, would probably stimulate the invasion of Parthenium on most economical lands such as arable and grazing lands. In this study, we assessed the distribution and abundance of a fearsome Parthenium weed in MZ of Benishangul Gumuz region, Northwest Ethiopia. The potential means of spread for P. hysterophorus in MZ includes road construction, vehicles, animals, rivers/irrigation water, and fruit/forest seedlings at Parthenium infected at nursery. Due to the Grand Ethiopian Renaissance Dum and Beles Sugar factory, there was a massive road construction extending from Chagni to Mandura through Dangur and Mandura through Jawi.Thus, construction vehicles have crossed several agricultural fields, searching for soils and stones for the work.
These vehicles were likely to distribute the weed from cities to rural areas. Besides, the highly populated animals in the zone contribute to the spread of the weed while feeding the infested field. According to the present study, the P. hysterophorus was less distributed in MZ but aggressively invaded roadsides, wastelands, around habitation, and market places in four cities . Similarly, many scholars have reported that P. hysterophorus and other IAPS usually invade wasteland and roadsides in the cities at the phase of introduction The reason why they always appear in the city, and roadside is that their introduction is highly related to human activity . After establishment, they eventually start moving to the most economically important areas like crop fields and grazing land. Vehicles, livestock, and road construction play a significant role in spreading the P. hysterophorus in particular and other IAPS in general. Habitats that had continually disturbed and have low diversity become extremely vulnerable to the invasion . Mosissa and colleagues have surveyed in 2010 and reported five invasive alien plant species in MZ.